How to fix the “trustd” process causing high CPU use on your Mac

If you’ve recently reinstalled or upgraded macOS you may have encountered an issue where the “trustd” process consumes lots of CPU resources, causing bad battery life and overheating on your Mac. It may be accompanied by the “nsurlsessiond” process, among others. So read on to find out what trustd does and how you can stop it hogging your Mac’s CPU resources.

What does “trustd” do?

The process manages certificates for HTTPS as well as Mail, the App Store and others. It also manages Keychains, which is where your Mac stores all kinds of passwords such as WiFi, iCloud, App passwords, user passwords etc. So it’s certainly not something you’d want to do away with, if that were even possible. However there’s no reason it should be hammering your Mac’s CPU, so we’ll need to fix it one way or another.

How can you confirm “trustd” is the cause of the high CPU use issue, and not another process?

As mentioned earlier, the “trustd” process may be accompanied by other processes such as “nsurlsessiond” and “syslogd”. So how can you confirm it’s trustd specifically causing the issue? Restarting your Mac will restart all processes, so that won’t narrow it down. The best way to confirm is to run the below command in the terminal, which manually kills off and restarts the trustd process:

sudo launchctl kickstart -k system/com.apple.trustd

If your Mac’s CPU usage drops right down after restarting trustd, then it’s definitely the cause of the issue. Read on to find out how to fix it.

How to fix the runaway “trustd” process

As the trustd process is related to the keychain, deleting the “system.keychain” file has been known to solve the issue for users. While the keychain will recreate itself, you will lose some saved credentials such as your WiFi passwords. Follow the steps below to delete the “system.keychain” file:

Browse to the “Keychains” folder

The “Keychains” folder is located in the “Library” folder, which is somewhat hidden. To access it press Command-Shift-G on your keyboard and enter “/Library” in the box that comes up:

From the Library folder, go to the Keychains folder.

Backup & delete the “system.keychain” file

In our testing deleting the “system.keychain” file didn’t cause any adverse affects, however it’s important to make a backup just in case. Simply copy system.keychain to another directory on your Mac then drag the original to the trash. You’ll most likely be prompted for your admin password to complete this.

Restart your Mac

Now that system.keychain is deleted, restart your Mac and the file will be re-generated. If any unexpected issues occur you can always delete the new keychain file and put the old one back.

What if deleting system.keychain doesn’t fix the issue?

If the issue is still occurring after deleting system.keychain, or if deleting it caused other issues, you will need to blow away macOS and reinstall it. Follow these instructions from Apple, and make sure you complete the option specified in the article to erase the disk first. In our testing installing macOS over the top of an existing installation did not resolve the issue, so you will need to wipe your Mac’s disk and start completely fresh.

Do you have another solution?

Did you try something else which fixed the runaway trustd issue? Then please share it in the comments section below to help out other users who are experiencing the issue!